In a current orthogonal frequency division multiplexing (OFDM/OFDMA) wireless communication system, if there's data waiting to be sent, a user terminal, synchronized with a base station already, needs to send an RRI to the base station, so as to request the base station to allocate an uplink transmission resource (hereafter referred to as a time and frequency resource) adapted to bear the data. The RRI is also called a scheduling request indicator (SRI). After receiving the RRI, if the base station allocates a time and frequency resource for the user terminal, the base station sends resource allocation information to the user terminal. The user terminal also requires a time and frequency resource when sending the RRI, so the base station needs to allocate the time and frequency resource adapted to bear the RRI for the user terminal in advance.
There's a method for allocating a time and frequency resource adapted to bear an RRI for the user terminal. In this current method, a time and frequency resource separately reserved is shared by certain user terminals to send the RRIs. The RRI of each user terminal employs all the OFDM symbols in one time slot, and the RRIs of different user terminals are differentiated through different time and frequency two-dimensional code sequences. The time and frequency two-dimensional code sequences refer to code sequences two-dimensionally extended in time domain and frequency domain, and any two of the code sequences are orthogonal or quasi-orthogonal with each other.
During the process of realizing the present invention, the inventor(s) finds that the conventional art at least has the following problems. A base station needs to reserve a relatively fixed time and frequency resource of all the time and frequency resources. The relatively fixed time and frequency resource is allocated for a data part and a pilot part of an ACKnowledgement (ACK) signal, and will be only used by the ACK. Besides, in the foregoing current method, the base station also needs to reserve a time and frequency resource which is allocated for the user terminal to bear the RRI. In other words, the time and frequency resources reserved by the base station include not only the time and frequency resource for the data part and the pilot part of the ACK, but also the time and frequency resource for the RRI, which increases the overhead of the reserved resource distinctly, and further reduces the time and frequency resources that the base station could dynamically allocate for an uplink user data.